A magnetic recording head is disclosed, which is provided with a side shield to shield a leaked magnetic field generated by a magnetic pole thereof, in a published US patent application (see USP-A 2005/0237665).
However, when a spin torque oscillator is embedded in the magnetic recording head disclosed in the published US patent application, the side shield is not capable of sufficiently absorbing a radio frequency magnetic field. This is due to an RF magnetic field as high as 15 GHz to 30 GHz which a spin torque oscillator generates. That is, the RF magnetic field leaks from the side shield. Hereinafter, a spin torque oscillator is referred to as “STO”. The “radio frequency” is referred to as “RF”.
Therefore, when writing is performed onto a magnetic recording medium using such a magnetic recording head with STO embedded, the RF magnetic field leaks to tracks adjacent to the targeted track of the magnetic recording head. There is a possibility that the RF magnetic field having leaked to the adjacent tracks erases data previously recorded on the magnetic recording medium. Furthermore, there is another possibility that the RF magnetic field having leaked to the adjacent tracks deteriorates the magnetic recording medium. As a result, it is problematic that the bit error rate of the adjacent tracks rises.
This will make it difficult to perform an RF field-assist recording with higher recording density.